Safety device for elevators.



No; 658,853. 1 Patent ed Oct. 2, I900.

- w. LESSING. SAFETY DEVICE FOR ELEVATORS.

(Application filed Apr. 8, 1896.) (IodeL) 3 Sheets-Sheet l.

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(Application medkA n a, 1896.)

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No. 658,853. Paten te d Oct. 2, 1900.

w. LESSING.

SAFETY DEVICE FOR ELEVATORS.

(Application filed Apr.

model.)

WITNESSES ZWM ATTORNEYS UNITED STATES l PATENT OFFICE.

WILHELM LESSING, OF RINGEBRAUK, GERMANY, ASSIGNOR TO HEINRICH STABY, OF UNN'A, GERMANY.

SAFETY DEVICE FOR ELEVATORS.

SPECIFICATION formingpart of Letters Patent No. 658,853, dated October 2, 1900- Application filed April 3, 1896. Serial No. 586,121. (ModeL) I To all whom it may concern:

Be it known that I, WILHELM LESSING, a subject of His Majesty the Emperorof Germany, and a resident of Ringebrauk, near Unna, Westphalia, Germany, have invented a new and useful 1m provement in Safety Devices for Elevators, of which the following is a full, clear, and exact description, when taken in connection with the accompanying drawings, which form a part thereof, and in which Figure 1 represents a-front elevation of the framework of an elevator embodying my invention} Fig. 2, a longitudinal vertical section on lines 2 2 of Fig. 3; Fig. 3, a plan View; Fig. 4, an end View; Fig. 5, a transverse vertical section on lines'5 5 of Fig. 1; Fig. 6, a longitudinal central section of a modified form of my invention; Fig. 7, a similar end View to Fig. 4 with the parts in a different position;

Fig. 8, an enlarged view of a portion of Fig. a; Figs. 9 and 10, side elevation and plan view of a detail of Fig. 6.

In all figures similar characters of reference represent like parts.

This invention relates to mining-cages or cages for elevators and lifts, and more particularly pertains to an automatic safety brake mechanism which comes into operation upon the rupture of the supporting-cable or other accident tending to drop the cage.

The invention consists in brake-blocks adapted to grasp the guide beam or rope upon which the elevator runs and to hold by' friction and positive mechanical devices the cage rigidly on said beam or rope, together with the mechanism for automatically operating the brake-blocks upon the severance of the cable or other accident which releases the elevator from its normal support.

A further feature of the invention is a sliding and spring connection between the cage and the box or mounting of the safety brake mechanism, which is otherwise independent of the cage, so that the cage is allowed a slight further movement and more gradual stoppage upon the locking of the brake mechanism to reduce the shock of the sudden stoppage, both upon the guide-beams which become the support for the cage and upon the cage itself. Moreover, the safety braking mechanism is provided with a'locking device which prevents the accidental operating of the brake-blocks upon the ordinary stoppings and startings of the cage and during any irregularities in the movements of the cage when the guide-beams may be crude or inaccurate, all of which improvements are more fully set forth, together with minor features, hereinafter.

The elevator as a whole may be divided into two parts, the cage proper and the brake box, in which is mounted the brake mechanism.

The cage pr0per.ln the drawings the upper portion of the framework'of the cage is represented by the parts designated by the numerals 1, 2, 3, 4E, and 5. The horizontal beams 1 are the top of the cage and are connected by cross-beams 2, Figs. 2 and 3, while depending therefrom are the corner uprights or standards 3 and the intermediate uprights 4 and braces 5. (Shown broken away, as the lower part of the framework of the cage is not illustrated.) This upper portion of the frame of the cage is provided with'a yielding connection with a box or auxiliary frame on which is mounted the automatic safety brake mechanism, so that when the safety-brakes are suddenly applied the cage may be allowed a slight further movement and, having a spring-support, will be more gradually stopped.

Mounting for brake mechanism-This box or mounting for the brake mechanism is formed as follows: Two horizontal beams 6- extend above the upper beams 1 of the cageframe, while below the beams l of the cage are two more beams 7, parallel to the beams 6. To the ends of the beams 6 and 7 are riveted or otherwise secured two end plates 8, the beams 6 and 7 and plates 8 making a rigid box-like f rame,with which the cage-frame has a yielding sliding connection. Cross-beams 9 extend between the two lower beams 7 of the brake-box, and are located beneath and parallel to the cross-beams 2 of the cageframe. Uprightspindles10arerigidly mounted on these cross-beams 9 and extend up to and through the cross-beams 2, in which they are capable of sliding vertical movement in openings 11 in the cross-beams. Spiral springs 12 surround the spindles l0 and bear on the upper side of the cross-beams 9 of the brake-box and the under side of the crossbeams 2 of the cage-frame and constantly tend to keep the cage-frame and brake-box in the relative position shown in Figs. 2, 5, and 6, while upon the abrupt stoppage of the brake-box the cage maybe drawn downward by its weight or momentum to the position shown in Fig. l,until the tension of the springs 12 overcomes the momentum of the cage and gradually bring it to a standstill.

It may be added that the upward movement of the cage-frame under the tension of the springs 12 is limited by the beams 1 of the cage coming in contact with the under side of the beams 6 of the brake-box, Figs. 2, 5, and 6.

Broke mechanism. On the outside of each of the end plates 8 of the brake-box are guides 13, formed of angle-irons, between which are adapted to be the guide-beams B of the shaft in which the elevator or lift runs. In the construction shown in the drawings the guidebeams are two in number, one on each end of the elevator, Fig. 7; but it will be obvious that the number and form of these guidebeams may vary and even ropes may be employed by merely changing in unessential details the construction of the device. Below the guides 13 on each plate 8 (but independent thereof) are a pair of brake-blocks 14, formed of metal and hollow, each block being pivotally connected to two toggle or brake arms 15, which in turn are pivoted in housings 48 to the outside of plates 8, Fig. 4. By means of the toggle-arms 15, pivoted to each brake-block, the brake-blocks as they are raised or lowered are moved to or from each other, while still retaining a parallel position. Between these brake-blocks extend the guidebea-ms B, Fig. 7, and when the brake-blocks are in their normal position-21. e., swung downward (shown in Fig. 4)the cage may run freely on the guide-beams; but when the brake-blocks are raised they will swing toward each other and grip by friction the guide-beams between them, Fig. 7, and when once the beams are so gripped the weight of the whole elevator will tend to swing the brake-blocks more closely together to hold the beams still more tightly.

In order that the action of the brake-blocks 14 may be more perfect, there is provided on the inner ends of the upper toggle-arms 15 sharp edges or teeth 44, (see Figs. 4 and 7,) which as the brake-blocks 14 are swung upward bite into and grip the sides of the guidebeams. Moreover, at the lower ends of the brake-blocks are sockets 45, into which may be fixed india-rubber or other suitably-made scrapers 46, by means of bolts 47, Fig. 4. These scrapers 46 assist in keeping the surfaces of the guide-beams clean, and. when the brakeblocks are applied scrape the beams and by friction assist the brake-blocks in getting a proper grip thereon.

Supporting mechanism for the cage.The whole elevator is adapted to be suspended by a cable or rope, (not shown,) and the automatic safety-brake is constructed to be immediately brought into operation upon the rupture or other disconnection of the cable from the elevator. The cable is secured to the elevator by means of acentral suspensionbolt 16, with its eye 17, Fig. 4. The bolt 16 passes freely through a middle cross-beam 18, extending between and attached to the beams 1 of the cage, and carries at its lower end a disk or block 19, held thereon by a nut 20 or formed integral with the suspension-bolt 16. Below the cross-beam 18 is another disk 21, through which the suspension -bolt freely passes, and between the disks 19 and 21, about the suspension-bolt 16, is a powerful coiled spring 22. The cage is therefore supported by the suspension-bolt 16, acting through the spring 22 on the cross-beam 18 at the top of the cage-frame.

A modification of the spring connection between the suspension-bolt 16 and cross-beam 18 is shown in Fig. 6, where instead of a coiled spring one or more flat springs 22 are provided, rigidly secured by bolts 23 and nuts 24 to the under side of the cross-beam 18, which in this case is made of more depth than in the first form. To the outer end of the spring or springs 22 are secured cross-bars 25, which bear on the outer ends of-a rocking beam 26, pivoted in the block 19, herein shown formed integral with the lower end of the suspension-bolt. As the rocking beam 26 is secured to the suspension-bolt 16, the Weight, of the cage is communicated from the cross-beam18 to the bolt 16, as before, through the spring or springs 22.

When the cage is in its normal position i. 6., suspended by the cable-the strain on spring 22 (which is then compressed) may be relieved by the block 19 coming in contact with the under side of the cross-beam 18, the elevator being carried then by block 19 of the suspension-bolt 16, directly supporting the cross-beam 18 of the cage, or, as in the form illustrated in Figs. 1 to 5, acollar 28 may be rigidly connected to the suspension-bolt 16 and adapted to come in contact with the disk 21 on the under side of cross-beam 18 when the cage is supported by the cable. When the cage is thus supported, the brake-box lies directly on the cage, as shown inFigs. 2 and 6; but when the support of the cage is discontinued by the breaking of the cable, 850., the brake mechanism in the brake-box will immediately be put into action and the brakebox stopped, while the cage is brought more gradually to a stop by the spring connection between it and the brake-box, as described above.

M 'echam'sm for actuating the brahe-bZ0chs.-- At the lower end of the suspension-bolt 16, extending either through the block 19, Fig. 6, in which the rocking beam 26 is pivoted, or

through a simple block 29, secured to the lower end of the suspension-bolt in any desirable manner, is a flat spring-bar 30, the

outer ends of which are pivoted to or coiled oted latches 41, adapted to swing through the around the lower ends of links 31. The upper ends of the links are pivoted to levers 32, which in turn are pivoted on a standard or bracket 33, secured to the inner sides of the end plates 8 of the brake-box. Extending inwardly through two openings 34, Fig. 4, in the end plates 8 are two studs 35 and 36, rigidly secured to each of the brake-blocks 14, and cross-rods 37, secured to ends of levers 32, extend between the upper studs 35 and the lower ones 36, as shown in Figs. 2, 3, and 5. As the levers 32 are swung on their pivots the cross-rods 37 force the studs 35 upward or the studs 36 downward. Therefore when the upward force exerted by the cable is removed from the suspension-bolt 16 the spring or springs 22force the lower end of the bolt downward in relation to the elevatorinto the position shown in Figs. 1 and 2, and the springbar 30 is thereby also forced downward; but the downward movement of the spring-bar 30 is communicated by the links 31 to the inner ends of levers 32, and the outer ends of levers 32 are swung upward, forcing, by means of cross-rods 37, the studs 35 upward. As the studs 35 are rigidly secured to the brakeblocks 14, the latter are raised (as before shown) and pressed inward by the toggle-arms 15, Fig. 7, to grip the guide-beam between them and stop the descent of the brake-box. The cage, as already shown, is brought to a more gradual stop by its spring connection with the brake-box.

To release the brake mechanism,the raising of the suspension-bolt 16 reverses the action of spring-bar 30, links 31, and levers 32', so that the outer ends of levers 32 press the other studs 36 downward and force the brake-blocks 14 downward and away from the guide-beams to allow the elevator free movement on the guide-beams, Fig. 4.

The studs 35 and 36 may be placed some distance apart, as shown in Fig. 8, so that a considerable upward movement of the crossrod 37 on the outer end of levers 32 is necessary to bring them into contact with studs 35 and force the brake-blocks 14 upward. This considerable movement is only attained when the cable is ruptured or the suspension-bolt 16 is relieved of practically its whole support. On the other hand, slight variations in the upward pressure on the suspension-bolt 16, such as takes place when the cable somewhat overruns the elevator, is not enough to operate the brake-blocks.

A modification of the levers 32 and interacting parts on the brakeblocks 14 is shown in Figs. 6, 9, and 10. The levers 32 are rigidly connected to a shaft 38', journaled in the brackets or standards 33, to rotate with the levers 32. Also rigidly mounted on the shaft 38 are two bell-crank levers the lower arms 39 of which extend under and are adapted to lift the studs 35 when the inner ends of levers 32 are swung downward. To the upper ends 40 of the bell-crank levers there are pivl end .plates 8 and engage catches 42 on the inner side of the brake-blocks 14 when the inner ends of levers 32 are swung upward. Flat springs 43 are secured to the upper arms 40 of the bell-crank levers to force the latches 41 into engagement with the catches 42. In this construction, when the suspension-bolt 16 is supported by the cable and by means of spring-bar 30, links 31, and levers 32, the shaft 38 and bell-crank levers are turned so that the latches 41 engage the catches 42, and the brake-blocks are held in the downward and open position, Fig. 6; but when the suspension-bolt 16 is released from support the action of the parts is reversed and the lower arms 39 of the bell-crank levers comein contact with studs 35 (studs 36 being omitted in this construction) and force them and the brake-blocks 14 upward, releasing at the same time the latches 41 from engagement with the catches 42, Fig. 9.

Having now described my invention, which may be varied somewhat in construction without departing from the spirit thereof, what I claim, and desire to secure by Letters Patent, is

1. The combination with the guide-beam or stationary member of an elevator or lift; of a traveling member; brake-arms pivotally mounted on said traveling member on opposite sides of said guide-beam; brake-blocks pivoted to the free ends of said brake-arms; and brake-operating mechanism connected to said traveling member common to said brakebloclks being adapted to engage the brakeblocks to raise the same, while the brakearms swing said brake-blocks toward each other to grip said guide-beam between them, substantially as described.

2. The combination with two or more guidebeams or stationary members of an elevator or lift; of a traveling member; brake-arms pivotally mounted on said traveling member on opposite sides of each of said guide beams; brake-blocks pivoted to the free ends of said brake-arms; brake mechanism connected to said traveling member adapted to synchronously directly engage said brake-blocks to raise the same while said brake-arms swing said brake-blocks, those adjacent to each guide-beam swinging toward each other to engage the respective guide-beams between them, substantially as described.

3. The combination with the guide-beams or stationary members of an elevator or lift; of a traveling member; brake-arms pivotally mounted on said traveling member and disposed in parallel series on opposite sides of each of said guide-beams; vertically-extendin g brake-blocks pivoted to each series of said brake-arms; levers mounted on said traveling member and adapted to directly engage with and operate said brake-blocks, and mechanism for operating said levers synchronously, substantially as described.

4. The combination with oppositely disposed guide-beams or stationary members of an elevator or lift; of a traveling member; brake-arms pivotally mounted on said traveling member and situated in parallel series, on opposite sides of each of said guide-beams; vertically-extending brake-blocks pivoted to each series of said brake-arms; two levers mounted on said traveling member and adapted to engage with and operate said brakeblocks; a yielding connection between said levers; and mechanism for operating said yielding connection to swing said levers; substantially as described.

5. The combination with the guide-beam or stationary member of an elevator or lift; of a traveling cage; braking devices adapted to engage said guide-beam; a suspension device for said cage; brake mechanism for operating said braking devices; a yielding c011- nection between said brake mechanism and suspension device and a yielding connection between said. braking devices and said traveling cage, substantially as described.

6. The combination with the guide-beam or stationary member of an elevator or lift; of a traveling cage; a support for said cage; a spring connection between said support and cage; brake mechanism adapted to engage said guide-beam and operated by the spring connection between said support and cage, said brake mechanism having separate mounting from said traveling cage; and a yielding connection between said cage and said mounting for said brake mechanism, substantially as described.

7. The combination with the guide-beam or stationary member of an elevator 0r lift; of a traveling member; brake-arms pivotally mounted on said traveling member and disposed in parallel series on opposite sides of said guide-beam; vertically-extendingbrakeblocks pivoted to each series of said brakearms; friction devices on said brake-blocks for engaging said guide-beam; and brake mechanism 011 said traveling member connected to said brake-arms to swing the same toward each other to engage said guide-beam with said brake-blocks and friction devices; substantially as described.

8. The combination with the guide-beam or stationary member of an elevator or lift; of a traveling member; brake-arms pivotally mounted on said traveling member and disposed in parallel series on opposite sides of said guide-beam; vertically-extendin g brakeblocks pivoted to each series of said brakearms; a lever mounted on said traveling member, adapted to engage said brake-blocks to swing the same to engage said guide-beam and to hold the same from such swinging; and mechanism for operating said lever, substantially as described.

9. The combination with the guide-beams or stationary members of an elevator or lift; of a traveling member; brake-arms pivotally mounted on said traveling member and disposed in parallel series on opposite sides of each of said guide-beams; vertically-extending brake-blocks pivoted to each series of said brake-arms; levers mounted on said traveling member, adapted to engage said brakeblocks to swing the same synchronously to engage said guide-beams and to hold the same from such swinging; and mechanism for operating said levers; substantially as described.

10. The combination with the guide-beam or stationary member of an elevator or lift; of a traveling member; two series of paralleldisposedbrake-arms pivotally mounted on said traveling member on opposite sides of said guide-beam; vertically-extending brakeblocks pivoted to each series of said brakearms; a lever mounted on said traveling member; studs on said brake-blocks on opposite sides of the end of said lever adapted to be engaged by said lever when swung in either direction; and mechanism for swinging said lever and holdingit stationary, substantially as described.

WILHELM LESSING.

Witnesses:

OTTO KoNIG, H. T. Hnss. 

